Ovarian cancer is the leading cause of death from gynecologic malignancy in western civilized countries, with an estimated prevalence in Europe and the U.S.A. of 752,600 in 2007 and 59,828 deaths yearly. Treatment and survival of the patients depend primarily on the stage of the disease. Of all ovarian cancer patients only 25% are diagnosed at an early stage while the tumor is confined to the pelvis. In these cases the five-year survival rate is 80% to 90% and the disease can often be cured by the combination of surgery and chemotherapy and are increasingly frequently referred to as type I ovarian cancer. Unfortunately, almost 75% of women affected have advanced stage disease with metastatic spread throughout the abdominal cavity or to retroperitoneal lymph nodes at the time of diagnosis; five-year survival rates fall to 19%-32% for advanced disease, despite maximum surgical effort and combination chemotherapy. This so called type II ovarian cancer is the deadliest cancer in women, even more aggressive than lung cancer.
Diagnostic procedures which require a non-surgical entry into the uterus are well known. One such procedure known as hysterosalpingography is a radiographic method for imaging the anatomical structures of the uterus and fallopian tubes.
Hysterosalpingography involves inserting a fine flexible catheter through the cervical canal and injecting a contrast medium, such as an iodinated fluid, into the uterus. Radiography is then carried out to provide imaging information pertaining to the subject uterus.
Another well-known diagnostic procedure which entails the non-surgical entry into the uterus is called saline contrast hysterosonography. This procedure also employs a fine flexible catheter that is inserted into the cervical canal of the uterus. The catheter in this procedure enables the physician or technician to inject a sterile saline solution into the uterus to expand it so that an ultrasound scanner can be used to sonographically observe the uterus.
The uterine cavity is in a sense a virtual space, because the anterior and posterior walls of the uterus are in direct contact to each other. Particularly in postmenopausal but also in non-pregnant premenopausal women the body of uterus containing the uterine cavity is very small. The cavity itself has a triangular shape measuring only app. 3 cm in length and app. 2 cm at the roof. When a fluid gets dispensed into the cavity, it immediately evacuates through the fallopian tubes into the peritoneal cavity and the dispensed fluid cannot be retrieved anymore. Furthermore on aspiration the opening of catheters tend to get obstructed by loose tissue from the lining of the cavity called endometrium or by blood clots frequently present in the uterine cavity.
Cells shed from the lining of the fallopian tube and ovary get transported into the cavity and are of great interest for detecting premalignant and malignant changes in these tissues. These cells are extremely little in number making it difficult to sample them. All sampling devices for the uterine cavity to date are designed to sample tissue of the lining of the uterine cavity to detect premalignant or malignant changes of the endometrium. For the detection of the minute number of cells shed from the lining of the fallopian tube and ovaries and that found their way into the uterine cavity a sampling device is desired that would allow retrieving those loose cells with as little as possible contamination of endometrial tissue.
To overcome these problems a catheter is desired that has a very short tip to fit into the small space of the uterine cavity, that allows for simultaneous flushing of fluid into the uterine cavity and proximal tubes and aspirating the fluid at the same time, preventing the fluid to evacuate through the fallopian tubes. To reduce the risk of obstruction the channels should have more than one opening ideally pointing into different directions. To prevent the fluid from back flowing through the cervical canal, a small balloon would be desirable.
WO03033045 discloses a catheter with suction capability to obtain a biosample. Specifically, the catheter is designed for collecting prostatic fluid from the prostatic urethra and/or the membranous urethra. To obtain a biosample, the catheter exhibits biosample entry ports (25) which are positioned along the elongated body. Additionally the catheter has a urinary drainage port (26). Therefore, the catheter according to WO03033045 is not suitable to simultaneously dispense a diagnostic fluid and retrieve a sample of the dispensed fluid at once.
PCT/EP2013/051899 discloses a non-invasive method for the diagnosis of adenocarcinoma or their precursor lesions of ovaries, fallopian tubes and endometrial lining in a female subject by analyzing cells of said subject wherein a uterine catheter designed for non-invasive rinsing of the uterine cavity and collecting a sample of the rinse.
One problem associated with said catheters of this design is that they have a closed tip which makes it difficult to retrieve a sample of the dispensed fluid, representing a lavage of the fallopian tubes and uterus. Therefore, a catheter which allows for simple and reproducible retrieving a sample from the dispensed fluid is desirable.